Thermal energy is added to four identical<span> 1.0 kg </span>samples of water<span> at room temperature. Which of the following </span>increases in each sample<span>? average charge of an electron; average density of </span>a<span> nucleus; average mass of </span>a<span> proton; average speed of </span>a<span> molecule. Your answer: -. Answer: D - average speed of </span>a<span>molecule.</span>
Answer: The frequency heard will be f = 275.675Hz
Explanation: When an object emitting sound is moving, it occurs a phenomenon called Doppler shift or Doppler effect. What happens is that the sound gets higher when the moving object comes closer the observer and becomes lower after it passes, This change is due to the quantity of waves that passes through an area in an unit of time.
The formula to calculate the Doppler effect is as follows
f = () · f₀
f is the observed frequency;
c is the speed of sound;
Vs is velocity of the source;
f₀ is the emitted frequency of source;
Substituting and calculating,
f = · 300
f = 275.675 Hz
Thus, the frequency heard by the police officer is 275.675Hz.
C.
remember
reactants ----> products
Explanation:
It is given that,
Velocity in East,
Velocity in North,
(a) The resultant velocity is given by :
(b) The width of the river is, d = 80 m
Let t is the time taken by the boat to travel shore to shore. So,
t = 16 seconds
(c) Let x is the distance covered by the boat to reach the opposite shore. So,
x = 48 meters
Hence, this is the required solution.